You may be aware of your car’s carbon footprint, but what about the emissions related to the concrete structures it drives over?
Wouldn’t it be great if concrete could be replaced with a material that is not only greener to produce, but could absorb carbon from the air?
That’s the claim behind an experimental cement alternative called Ferrock. Inventor David Stone said he stumbled upon what would become Ferrock while working on a Ph.D. in environmental chemistry at the University of Arizona.
After an experiment to keep iron from rusting went wrong, he was left with a small, but improbably hard, rock.
Since then, Stone has worked to develop Ferrock–named for the iron it contains–as an alternative to cement, the manufacture of which accounts for an estimated 5% of global carbon-dioxide emissions.
Ferrock doesn’t require the high heat needed to manufacture cement, and it uses recycled materials. The iron comes from the waste of steel mills, and silica from recycled glass bottles.
Carbon dioxide is added during the manufacturing process to harden the Ferrock, making it a “carbon-negative” material, according to Stone.
That property caught the attention of the U.S. Environmental Protection Agency (EPA).
The EPA gave Stone more than $200,000 in grants for demonstration projects.
Stone has a patent for Ferrock, and founded a company called Iron Shell to promote its use.
Tests by Arizona State University researchers have shown Ferrock to be up to five times stronger than conventional concrete made with Portland cement.
